1. Field of the Invention
The present invention relates to a vehicle-pedal backward-displacement preventing device for preventing a depressible portion of an operating pedal from being backwardly displaced toward a driver's seat in the event of displacement of a dash panel toward the driver's seat.
2. Discussion of Prior Art
There has been proposed a vehicle-pedal backward-displacement preventing device having: (a) a pedal bracket which is integrally fixed to a dash panel through a plurality of attachments provided in the pedal bracket and spaced apart from each other in a vertical direction, and which is provided with a support portion extending toward a driver's seat; (b) an operating pedal disposed pivotably in the support portion of the pedal bracket, and having a depressible portion which is provided in its lower end portion and which is to be depressed whereby the operating pedal is operated; and (c) a guide member disposed in relation to the pedal bracket and a vehicle body member, and restraining, in event of backward displacement of the pedal bracket together with the dash panel toward the driver's seat, the depressible portion of the operating pedal from being backwardly displaced toward the driver's seat, by causing a distal end portion of the pedal bracket to be downwardly pressed as a result of displacement of the pedal bracket relative to the vehicle body member.
As an example of the vehicle-pedal backward-displacement preventing device, JP-H10-175492A describes a device for preventing a backward displacement of a brake pedal as the operating pedal. In the described device, the support portion of the pedal bracket extends in an obliquely upward direction, and is connected at its distal end portion to the guide member (slide plate) that is fixed to an instrument panel reinforcement member as the vehicle body member. In the event of displacement of the dash panel toward the driver's seat which displacement is caused, for example, with impact of a large load to the dash panel in a direction from the vehicle front to the rear, the pedal bracket is disconnected from the guide member, and the distal end portion of the disconnected pedal bracket is forced by the guide member to downwardly displaced. As a result of the downward displacement of the distal end portion of the pedal bracket, the pedal bracket buckles to be bent, while its lower attachment buckles to be crushed, whereby the brake pedal as the operating pedal is pivoted about a fulcrum provided by its connected portion at which the brake pedal is connected to an operating rod. The brake pedal is thus pivoted about its connected portion as the fulcrum such that its depressible portion is relatively displaced toward the front of the vehicle.
In recent years, there has been studied an employment of a pedal bracket that is formed of a synthetic resin such as glass-fiber reinforced resin, for example, for the purpose of reducing its weight. Such a resin pedal bracket is provided with a rib or other reinforcing means for obtaining a predetermined degree of rigidity, and the provision of such reinforcing means makes it difficult to cause the pedal bracket to buckle, thereby problematically resulting in an impossibility to sufficiently prevent the backward displacement of the operating pedal. Although it might be possible to construct the pedal bracket with a reduced rigidity for enabling it to buckle, the reduction of the rigidity could cause the pedal bracket to be deformed by a reaction force generated in a usual operation of the operating pedal. That is, it is difficult to establish a suitable degree of rigidity which permits the pedal bracket to buckle in the above-described event while avoiding deformation of the pedal bracket in a usual operation of the operating pedal. Further, in the device described in JP-H10-175492A, the lower attachment is arranged to be able to buckle in the above-described event, so that the pedal bracket can be inclined owing to a difference in deformation amount between the buckling lower attachment and the upper attachment that is compressively deformed. However, the operating pedal can not be sufficiently pivoted only by the inclination of the pedal bracket, which inclination depends on the difference in the deformation amount between the upper and lower attachments.
The present invention was made in the light of the background art discussed above. It is therefore an object of the invention to make it possible to appropriately obtain an effect of prevention of backward displacement of the operating pedal even where the pedal bracket does not buckle.